Named as middle formation of Upper Cretaceous Mesaverde group in main part, Book Cliffs coal field, Garfield and Mesa Cos, CO, Piceance basin. Type section measured at Book Cliff mine, SW1/4 sec 8, T10S, R99W, where it: is 1050+ ft thick; conformably overlies Sego sandstone (first used), lower formation of Mesaverde; consists of interbedded dark-brown, gray to black, carbonaceous to sandy shale, sub-bituminous to bony coal, gray, fine- to medium-grained (60-95 percent quartz, 15-30 percent feldspar) sandstone, individual beds of which vary from soft and friable to thin-bedded ledge-forming to massive cliff-forming. Several concretionary layers. Includes at its type: 1) Palisade coal zone at base, a 70 ft thick carbonaceous shale and coal with one gray sandstone near its mid section; 2) Rollins sandstone member, 71 ft thick, a massive, cliff-forming white coarse-grained to sugary textured unit that is overlain by; 3) Cameo coal zone, 37+ ft thick carbonaceous shale and coal whose upper contact is about 626 ft below top of Mount Garfield. Thinnest section 970 ft thick is at West Salt Creek. Conformably underlies Hunter Canyon Formation (new), upper formation of Mesaverde. Hunter Canyon sandstones are more numerous, coarser, grayer, massive than Mount Garfield sandstones. Of littoral, fluviatile, estuarine, continental origin. Geologic map. Regional correlations described.

Source: GNU records (USGS DDS-6; Denver GNULEX).

Terms "Mt. Garfield and Hunter Canyon formations" not used. Author applies the name Neslen facies (formerly Neslen member of Price River) to all the coal-bearing rocks of the Price River formation and the name Farrer facies (formerly Farrer member of Price River) to all the non-coal-bearing rocks of the Price River. Term Price River used along Book Cliffs from Castlegate area in Carbon Co, UT in the Uinta basin, across Emery and Grand Cos, UT in the Paradox basin, to Cameo on the Colorado River, Mesa Co, CO in the Piceance basin. From Thompsons, UT near the CO border, Price River is divided into (ascending): Castlegate (formerly Castlegate sandstone member), Sego (formerly Sego sandstone member), Corcoran (new), Cozzette (new), and Cameo (new) members. West of Thompsons, Price River divided into (ascending): Castlegate member and the overlying shale, sandy shale, and lenses of sandstone.

Source: GNU records (USGS DDS-6; Denver GNULEX).

Divided into the Corcoran, Cozzette, and Rollins Sandstone Members along the Book Cliffs, Garfield and Mesa Cos, CO in the Piceance basin. Corcoran and Cozzette newly assigned to Mount Garfield. Overlies Sego Sandstone; underlies Hunter Canyon Formation. Is the equivalent in CO of the Neslen and lower part of Farrer Formations of adjoining Book Cliffs area of Grand Co, UT. Cross sections. Correlation chart. Measured sections. Of Late Cretaceous age.

Source: GNU records (USGS DDS-6; Denver GNULEX).